Hello!
It was explained to us by friends who live in Mazatlan full time: The water source and water that comes from it are usually just as clean as in the U.S., it's after the the water gets in the water system that the buggies get into the water you may drink. Cracked water delivery pipes that allow germs in appear to be a big problem. We always drank bottled water including from those big 5 gallon bottles of Hibiscus, limon (lime) etc you can buy for the home or can get by the cup at the mercado. Ice was also not a problem for us and many of the people selling drinks advertised they had used bottled water for their ice. Fresh squeezed juice was delightful as well as smoothies. You can watch the Market sellers peel the fruit as they are making it. If you are worried, we were told to bring pepto bismol and take it 5 times a day to fend off gastrointesitinal organisms.
